Composition fok waterproofing



14 Claims. 1

This invention relates to theauaterLfinw, Portland cement concrete and general masonry construction and particularly to improved compositions for rendering such types of construction impermeable to water.

Portland cement concrete and mortar are mixed before use with water in excess of that required for the normal processes of hardening and setting. This excess water is evenly distributed throughout the mass of concrete or mortar and as it evaporates leaves unoccupied space in the form of fine capillary pores. It is the natural capillarity of this porous structure that influences the absorption and permeation of water into Portland cement concrete and mortarl Heretofore various methods have been used to treat concrete mortar and masonry in buildings and engineering structuresto prevent penetration of moisture. Through the years experience has demonstrated that one of the most effective processes is the .so-called Iron type of waterproofing, which employs iron that is in a finely divided state capable of oxidation In this process the finely divided iron is mixed .with approximately 5% by weight of ammonium chloride and sufiicient water added to form a slurry, which is applied by brushing. Th iron particles are drawn into the pores of the masonry surface through the wetting action of the water in which they are suspended and the mechanical force of brushing, and through the natural and normal process of oxidation are changed to a I hydrated oxide with a corresponding increase in molecular volume.

The se of this composition, however, is attended with practical diificulties due to the tend ency of the dense particles of iron to settle to the bottom of the container in which they are mixed with water. On account of this precipitous settling it is necessary to continuously stir the mixture during application, and brush it on quickly. Even so, several applications are necessary to develop a satisfactory film.

The several objects of this invention therefore are:

a. To improve physical suspension of the fine particles of iron in the water.

b. To increase the thickness of the waterproof CROSS REFERENCE UNITED STATES PATENT OFFICE COMPOSITION FOR WATERPROOFING MASONRY Ralph Eugene Madison and Frederic Arthur Fairbrother, Jr., Detroit, Mich., assignors to Devoe & Raynolds Company, Inc., New York, N. Y., a corporation of N ew York No Drawing. Application July 1,1948, Serial No. 36,416

(A) IRON The composition of this invention contains iron of a particle size that is freely drawn into the pores of the surface by water penetration, and then through oxidation increases in molecularvolume to further seal and waterproof the surface by forming a continuous oxidized film.

In the practice of this invention we find it advantageous to us a mixture of 100" iron and 200 iron where 100 iron is a crushed iron having the following screen analysis:

Per cent Held on mesh 1 Held on mesh 5 Held on 200 mesh 70 Through 200 mesh 24 and, "200" iron is a powdered iron having the m1- lowing screen analysis:

-- Per cent Held on 200 mesh 1 Through 200 mesh 99 It is a part of our discovery that a mixture of ,100 iron and 200" iron is better than either type alone. If 100" iron is substituted for all of the 200 iron, the resulting composition is dimcult to keep in suspension and oxidizes slowly. On the other hand ii all 200 iron is used, the suspension is improved at the expense of adhesion and oxidation. I

(B) EIECTROLYTE A number of compounds may be successfully used to accelerate the oxidation of the iron particies. It is known for example that good results can be obtained by using manganese dioxide, sulfur, iron sulfide, or ammonium alum for this pur- EXAMINER pose. It is particularly advantageous however to use ammonium chloride for most rapid and complete reaction.

The proportion of inorganic electrolyte used in our product is not critical and may be varied somewhat depending upon the salt used. Best results were obtained when we used between I and 'I%% ammonium chloride based on the weight of iron. If less than 1%% sal ammoniac is used the oxidation is proportionately incomplete. Likewise, if the content of sal ammorriac exceeds 7 the oxidation is deficient and the adhesion of the coating is definitely impaired. It is particularly advantageous to use ammonium chloride which amount shows the most impressive and pronounced results. Approximately 5% ammonium alum will also give very good results under certain conditions to be described hereinunder.

(C) WATER SOLUBLE CELLULOSE ETHER The water soluble cellulose ethers which we have found to be most satisfactory in the practice of this invention are methyl cellulose, hy-

droxy ethyl cellulose and'sodium carboxy methyl cellulose. These cellulose ethers may be obtained in different grades and viscosities and the amount added will vary according to the viscosity of the particular product used. This viscosity variation in centipoises, is illustrated in Table I which presents data on 2% aqueous solutions.

We have found that the viscosity of methyl cellulose and sodium carboxy methyl cellulose solutions is diminished by the addition of ammonium alum and for this reason prefer to use sal ammoniac in combination with these particular cellulose derivatives. Hydroxy ethyl cellulose may be used to equal advantage with either electrolyte.

The amount of cellulose ether employed in our composition may vary from approximately 1% to 3 by weight, and will vary with the viscosity and the particular product used. Thus approximately 1% by weight of methyl cellulose is sumcient, and as little as 0.2% of a high viscosity methyl cellulose will improve the iron suspension of our composition. It is well to use somewhat more hydroxy ethyl cellulose, usually from 1% to 3%. Here again however the exact amount will depend on the viscosity of the product used. Contrary to our expectations we have found that the presence of cellulose ethers in this concentration does not limit to any appreciable extent the desired penetration of the composition into concrete or other surfaces to which it is applied. The amount of water that will be required to obtain a brushable composition is also related to the viscosity and type of cellulose ether present. The weight of water required to reduce a composition containing 1000 .parts by weight of iron, parts by weight electrolyte and a cellulose ether to brushable consistency is shown in Table II.

Table II Parts P t Water to ercen give Cellulose Ether age brushable consistency 4000 cps. Methyl Cellulose l 300. 0 1500 cps. Methyl Cellulose 1 212. 6 50 cps. Methyl Cellulose 1 195. 0 5 cps. Hydroxy Ethyl Cellulose 1 145. 0 D0 3 212. 5 9 cps. Hydroxy Ethyl Cellulose 1 160. 0 c ig. Hydroxy Ethyl Cellulose l 192. 5 n 3 300. 0 cps. Hydroxy Ethyl Cellulose l 217. 5 l6 cps. Sodium Carboxy Methyl Cellulose l 222. 5 300 cps. Sodium Carboxy Methyl Cellulose...- 1 320.0 1000 cps. Sodium Carboxy Methyl Cellulose--. 1 335.0 16 cps. Sodium Carboxy Methyl Cellu1ose.- 3 460. 0 1000 cps. Sodium Carboxy Methyl Cellulose... 3

1 Altogether too much water needed.

In addition to improving the brushing characteristics of this composition, the cellulose ethers have another advantage in that they promote a more rapid oxidation. This may be illustrated by preparing an iron sal ammoniac composition with and without hydroxy ethyl cellulose. If these two formulations are applied to cinder blocks and each treatment given one application of water, the sample containing the hydroxy ethyl cellulose will show considerably faster oxidation. We have found that hydroxy ethyl cellulose has a pH range of 5.5 to 6.5 and believe that this acid reaction is responsible for the results observed. This rapid oxidation will also take place when the hydroxy ethyl cellulose is used with iron in the absence of sal ammoniac.

The following examples of specific compositions are intended to be illustrative only. It will be understood that other satisfactory formulations may be prepared by following the principles disclosed above.

EXAMPLE I Parts iron 50 200" iron 50 Ammonium alum 5 Hydroxy ethyl cellulose (55 cps.) 3

Approximately 300 parts of water are added to 1000 parts of the dry mix of Example I to obtain a product of brushable consistency.

EXAMPLE II Parts 100 iron 50 "200 iron 50 Sal ammoniac 5 Methyl cellulose (4000 cps.) 1

In applying the above composition from 300 to' 400 parts by weight of water should be added to 1000 parts of the dry mix,

A product that utilizes sodium carboxy methyl cellulose to improve oxidation and give homogeneous suspension is set forth in Example III.

GROSS EEFEREHCE 1000 parts of Example 111 should be mixed with approximately 320 parts of water before use.

The above description and examples are intended to be illustrative only. Any modification thereof or variation which conforms to the spirit of the invention is intended to be included within the scope of the claims.

We claim:

1. A composition of matter consisting essentially of particles of finely-divided iron capable of undergoing oxidation, from about 1%% to about 7%%, by weight, of an ammonium derivative selected from the class consisting of ammonium chloride and ammonium alum, and from about 1% to about 3%, by weight, of a watersoluble cellulose ether selected fromihe class consis ing 0 math cellulose. and sodium carboxy methyl cellulose,

said composition being in the form of a dry mixture and forming a waterproof coating when mixed with water and applied to a porous concrete surface.

2. A composition of matter as defined in claim 1 in which the water-soluble cellulose ether is hydroxy ethyl cellulose.

3. A composition of matter as defined in claim 1 in which the water-soluble cellulose ether is sodium carboxy methyl cellulose.

4. A composition of matter as defined in claim' 1 in which the ammonium derivative is ammonium chloride.

5. A composition of matter as defined in claim 1 in which the ammonium derivative is ammonium alum.

6. A composition of matter as defined in claim 1 in which the greater proportion of the particles of the finely-divided iron is of a size to pass through a 200-mesh screen and a substantial portion is of a size to pass through a IOU-mesh screen and to be held on a ZOO-mesh screen.

7. A composition of matter as defined in claim 1 in which the ammonium derivative is ammonium chloride and the water-soluble cellulose ether is sodium carboxy methyl cellulose.

8. A composition of matter as defined in claim 1 in which the ammonium derivative is ammonium chloride and the water-soluble cellulose ether is hydroxy ethyl cellulose.

9. A composition of matter as defined in claim ose W 1 in which the ammonium derivative is ammonium alum and the water-soluble cellulose ether is hydroxy ethyl cellulose.

10. A composition of matter as defined in claim 1 in which the ammonium derivative is ammonium chloride and is present in amount of about 5% and the water-soluble cellulose ether is sodium carboxy methyl cellulose and is present in amount of about 1%.

11. A composition of matter as defined in claim 1 in which the ammonium derivative is ammonium alum and is present in amount of about 5% and the water-soluble cellulose ether is hydroxy ethyl cellulose and is present in amount of about 1%.

12. A composition of matter consisting essentially of particles of finely-divided iron capable of undergoing oxidation, from about 1 /4% to about 7%%, by weight, of an ammonium derivative selected from the class consisting of ammonium chloride and ammonium alum, and from about 0.2% to about 3% of methyl cellulose, said composition being in the form of a dry mixture and forming a waterproof coating when mixed with water and applied to a porous concrete surface.

13. A composition of matter as defined in claim 12 in which the ammonium derivative is ammonium chloride.

14. A composition of matter as defined in claim 12 in which the ammonium derivative is ammonium chloride and is present in amount of about 5% and the methyl cellulose is present in amount of about 1%.

RALPH EUGENE MADISON.

FREDERIC' ARTHUR FAIRBROTHER, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,825,199 Patino Sept. 29, 1931 2,018,343 Bienfait Oct. 22, 1935 2,026,475 Larmore Dec. 31, 1935 2,316,745 Robertson et a1 Apr. 13, 1943 2,336,636 Peterson Dec. 14, 1943 2,346,624 Straus Apr. 11, 1944 

1. A COMPOSITION OF MATTER CONSISTING ESSENTIALLY OF PARTICLES OF FINELY-DIVIDED IRON CAPABLE OF UNDERGOING OXIDATION, FROM ABOUT 1 3/4% TO ABOUT 7 1/4%, BY WEIGHT, OF AN AMMONIUM DERIVATIVE SELECTED FROM THE CLASS CONSISSTING OF AMMONIUM CHLROIDE AND AMMONIUM ALUM, AND FROM ABOUT 1% TO ABOUT 3%, BY WEIGHT OF A WATERSOLUBLE CELLULOSE ETHER SELECTED FROM THE CLASS CONSISTING OF METHYL CELLULOSE, HYDROXY ETHYL CELLULOSE AND SODIUM CARBOXY METHYL CELLULOSE SAID COMPOSITION BEING IN THE FORM OF A DRY MIXTURE AND FORMING A WATERPROOF COATING WHEN MIXED WITH WATER AND APPLIED TO A POROUS CONCRETE SURFACE. 